This paper combines a study of the rock debris and 60/ 60 isotopic characteristics of basal ice sequences in three representative glaciers in South Georgia and concludes that the debris and ice has been entrained mainly by basal freezing . The size distribution of the rock debris is typical of crushing and abrasion, and reflects transport at the ice-rock interface. The 60/ 0180 relationships sh...

In this paper, the lift-law method was applied to design the axial flow pump. Based on Reynolds time-averaged N-S equations and standard k turbulent model, three-dimensional air-water bubbly flow in an axial flow pump impeller was simulated. Under the condition of bubble void fraction of 5%, pressure and void fraction distributions were respectively obtained, movement of bubbles in the impeller...

A Generalized Additive Model (GAM) is proposed to predict the pressure drop in a gas–liquid two-phase flow at horizontal, vertical, and inclined pipes based on 21 different dimensionless numbers. It fitted from 4605 points, considering fluid pattern classification as Annular, Bubbly, Intermittent, Segregated. The GAM non-parametric method reached high prediction capacity allowed great degree of...

Bubble-injection methods are considered to be a prospective approach to reduce skin-frictional drag for ships. To apply this technique for unsteady flows, we attempt to introduce a feedback loop of air injection in future applications. Hence, we wish to establish reduced order models of unsteady bubbly flows from the information at the bottom of the ship, but this must be achieved with a limite...

A bubbly flow in a vertical miniature tube is analyzed theoretically. The liquid and gas phase are co-current flowing upward. The gas phase is injected via a nozzle whose inner diameter is 0.11mm and it is placed on the axis of the tube. A force balance is applied on the bubble at its detachment. The set of governing equations are solved by use of Mathematica software. The bubble diameter and t...

Flow boiling of HFE 7000 in five parallel microchannels of 222 m hydraulic diameter, each containing a single row of 24 in-line 100 m pin fins, was investigated. High speed photography revealed the dominant flow patterns, namely, the bubbly flow, the multiple flow, and the wavy-annular flow. The interaction of the bubble with the pin fins during nucleate boiling from G 350 kg /m2 s to G 827 kg ...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Ari Poikonen Name of the doctoral dissertation Measurements, analysis and modeling of wind-driven ambient noise in shallow brack-ish water Publisher School of Electrical Engineering Unit Department of Signal Processing and Acoustics Series Aalto University publication series DOCTORAL DISSERTATIONS 18/2012 Field of research Und...

We report on measurements of energy spectra, second and higher order structure functions in bubbly turbulence. The void fraction is up to 2.9 % with an mean equivalent bubble size of 3-5 mm. We find the results of [I. Mazzitelli, D. Lohse, F. Toschi, Phys. Fluids, 15 L5 (2003)] qualitatively confirmed, i.e. a more pronounced energy enhancement on small scales than on large scales due to the pre...

In this paper, the two-dimensional Benney system describing long wave propagation of a finite depth fluid motion and the multi-dimensional Russo-Smereka kinetic equation describing a bubbly flow are considered. The Hamiltonian approach established by J. Gibbons for the one-dimensional Vlasov kinetic equation is extended to a multi-dimensional case. A local Hamiltonian structure associated with ...

In the absence of fractures, methane bubbles in deep-water sediments can be immovably trapped within a porous matrix by surface tension. The dominant mechanism of transfer of gas mass therefore becomes the diffusion of gas molecules through porewater. The accurate description of this process requires non-Fickian diffusion to be accounted for, including both thermal diffusion and gravitational a...